The following report grew out of a 10-week program in engineering systems design held at Stanford University and the Ames Research Center of the National Aeronautics and Space Administration during the summer of 1975. This program, sponsored jointly by NASA and the American Society for Engineering Education, brought together nineteen professors of engineering, physical science, social science, and architecture, three volunteers, six students, a technical director, and two co-directors. This group worked for ten weeks to construct a convincing picture of how people might permanently sustain life in space on a large scale.